Milling-cutter tooth.



No. 637,495. Patented Nov.. 2|, I899.

H. L. ARNOLD.

MILLING CUTTER TOOTH.

(Application filed Oct. 12, 1895.)

(No Model.)

NITED STATES ATENT FFICE.

HORACE ARNOLD, OF NEW YORK, N. Y.

MILLING-CUTTER TOOTH.

SPECIFICATION forming part of Letters Patent No. 637,495, dated November 21, 1899.

Application filed October 12, 1895. $erial No. 565,514. (No model.)

To all whom it may concern:

Be it known that I, HORACE L. ARNOLD, a citizen of the United States of America, residing at New York, (Brooklyn,) Kings county, State of New York, have invented certain new and useful Improvements in Milling-Machine Gutter-Teeth, of which the following is a specification.

The present invention relates generally to cutter-teeth or mills, and more particularly to the class known as inserted-tooth mills.

An inserted-tooth mill, as distinguished from the other class of mill known as the solid mill, consists in the main of a softmetal body or carrier adapted to be secured to a mandrel arbor or head and fitted or armed on its working surface with hardened and ground steel teeth, and by reason of the advantages of such a mill many different methods of holding the inserted mill-tooth in the mill body or carrier have been proposed, such as by the use of a wedge or screw, to the end that the holding be firm and certain up to the full strength of the tooth itself. In one instance also the inserted tooth was cylindrical in form and heldby driving into a radial hole in the soft mill-body, no provision having been made for renewing these teeth, as it was proposed to use the mill so long as efiective and then discard the teeth and body as a whole, to be replaced by a new mill, it not being practicable to refill the body with new teeth, for the reason that when a cylindric hole has once been filled with a steel plug or tooth the driving of such first tooth permanentlyincreases the diameter of the hole, and, again, with plain cylindric mill-teeth driven in plain cylindric holes very little hold can be had to pull the tooth out.

These improvements have for their object therefore to obviate the disadvantages heretofore incident to the use of inserted-tooth mills, to provide means by which the tooth may be readily removed from the mill body or stock and replaced by another which shall be securely fastened without change in the tooth-seat in said stock, and to generally improve the inserted-tooth mill without unnecessarily increasing its first cost; and to these ends the invention consists in the novel methods and structures hereinafter fully set forth.

The accompanying drawings illustrate a practical embodiment of the invention in its preferred and most complete form, in which- Figure 1 is a side elevation of the improved tooth. Fig. 2 is a front elevation, and Fig. 3 is a plan View, thereof. Fig. 4 is a sectional elevation of a tooth and portion of a mill body or stock, showing a mode of removing the tooth, the tooth being partially withdrawn from its seat. Fig. 5 is an enlarged transverse section on the line 5, Fig. 4, showing the effect of using a fluted tooth-shank of slightlygreater diameter than that of the tooth-seat. Fig. 6 is a perspective View of a tooth-blank for a tooth with a fluted shank. Fig. 7 is a plan and side view of an old form of tooth.

The improved tooth, Figs. 1 to 3, as usual, consists of a shank a, having formed at one end a cutting edge 2). In place of taking a diameter of the cylindrical tooth-blank for the cutting edges, as in the old form of tooth shown in Fig. 7, the cutting edge b is formed by a facing cut on a line drawn perpendicular to a diameter at three-quarters of the diameter length from a given point on the circumference of the blank, providing a tooth with one-half more depth in the line of efiect that is, in the direction of power and resistancethan the old tooth. The improved tooth also has much less tooth-face, and hence with a given out has less work to do than the old tooth of the same diameter of tooth-body and with one-half more strength to resist its work. To complete the formation of the improved tooth, the side-clearance cuts a are made, while the old tooth clears by virtue of its cutting edge being formed on a diameter of the blank.

To facilitate the removal of the inserted tooth from its seat in a body or stock, as d, Fig. 4, the improved tooth is provided with a hole 6, preferably tapped, the hole going clear through the entire length of the tooth. Its use may be twofoldfirst, to take a removable backing-out screw, as f, by means of which screw or similar contrivance, with its end, say, abutting against the bottom of the tooth-seat, the inserted tooth may at any time be backed out of its seat in the stock (I with ease and without injury to such seat, and, second, to cause the middle of the tooth to harden hard in tempering. \Vith the solid form of inserted tooth the middle of the tooth was often not so hard as the outer corners, especially at the root of the tooth. Teeth provided with holes through them have been found in practice to be more easily made of uniform form and extreme hardness than the solid teeth.

The improvement further contemplates the provision of means by which it is made possible to hold a renewal inserted tooth as firmly as the first tooth seated in a given tooth-seat is held, and to secure this firm second seating of a tooth in a cylindrical tooth-seat the means must be such as will make the tooth fill the seat. If the tooth has a plain cylindric body or shank, it will always enlarge the plain cylindric seat into which it is forced, and hence a second tooth of the same shank diameter will not fill a seat the second time so tightly as at first. Again, the cutting edges of the teeth are often set on a spiral, so that one corner strikes the cut in the metal first, in which case there is a very strong turning or twisting effect produced, tending to twist the cutter in its seat. To avoid these objections, the tooth or tooth body or shank is made larger in diameter than the seat which is to receive it, and the tooth or tooth-body is cut or otherwise formed with shallow flutes, ribs, grooves, as i, or the like to provide one or more portions of the tooth-body of less than the full diameter of the body. Thus in practice the mill-tooth blank maybe, but not necessarily, formed of two-cylinder shape, as indicated in Fig. (3, the shank portion a being of a diameter larger than the cutting-edge portion b, equal to twice the depth of the flutes, ribs, or grooves to be cut or formed therein, and with a cutter-seat, say, seveneighths 3-) of an inch diameter the cuttershanks are made fifteen-thousandths (.015) of an inch larger in diameter, and the flute out, say, one thirty-second of an inch deep at the corner, with eleven flutes in the circle, cut and land of about equal width. When such a fluted tooth-shank is forced in the first instance into a plain cylindric scat, it being understood, of course, that the shank, being of larger diameter than the seat, could not have been forced into the seat unless it be fluted or otherwise formed with low portions, the metal forming the walls of the seat between the tops or lands of the flutes swells inward to more or less fill the cuts, grooves, or low portions, as is indicated at 75 in Fig. 5. The tooth is thus forced to place easily and at the same time is very firmly held. This swaging in and swelling out action of the fluted tooth shank on the plain cylindric tooth-seat in the soft or untempered metal of the mill body or stock 61 displaces the metal of the walls of the seat at intervals around the seat and at the same time forces intervening portions of the walls inwardly toward the shank. It also produces a permanentlyelastic tool-seat, which will take a second duplicate tooth body or shank and hold it in practice as firmly as it held the first one.

To provide for certaintyin duplicating the inserted-tooth cutting edge for the same spiral or square position, a portion of the surface of the tooth-body is formed irregular with respect to the other portions of said surface-as, for instance, one of the flutes or grooves, as j, Figs. 2, 3, and 4, is cut wider than or differently shaped from any of the others, the fiuting or shaping of the toothbody being done before the cutting edge is formed. The position of the cutting edge may therefore be governed by the position of the wide flute, by which means all the three cuts needful to form the cleared cutting edge of the tooth are brought with certainty in a certain relation to the wide flute or groove or differently-formed portion j of the toothshank. As the tooth-shank swages very distinct and, comparatively speaking, deeplydefined grooves in the walls of the tooth-seat in the cutter body or stock, it is easy to replace a tooth and have the cutting edge of the renewal tooth stand precisely as the old edge stood.

hat is claimed is 1. The herein-described mill-tooth blank, the shank or body portion of which is of cylindric or regular polygonal shape, of greater diameter than the cutting-edge portion and is formed with a longitudinal portion or por tions of less than the full diameter of the shank to take the swell or swells of the walls of the shank-seat.

2. The herein described mill tooth, the shank or body of which of cylindric or regular polygonal shape is formed with a plurality of longitudinal portions of less than the full diameter of the shank to take the swells of the walls of the shank-seat.

3. The herein described mill tooth, the shank or body of which of cylindric or regular polygonal shape is formed with a plurality of shallow flutes or grooves to take the swells of the walls of the shank-seat.

4. The herein-described milltooth, the body of which of cylindric or regular polygonal shape is formed with a plurality of flutes or grooves and one of which is irregularly formed with respect to the others, for the purpose described.

5. A means of securing a tooth-shank in its seat, which consists in a seat of slightly less diameter than the tooth-shank, and a toothshank with one or more portions of less than the full diameter thereof, whereby when the shank is forced into its seat the Walls of the seat will be forced inwardly toward said shank at said portion or portions, as described.

6. The combination with a tooth-shank having longitudinal grooves orlow portions therein, of a holder or carrier having a cylindric seat therefor of slightly less diameter than In witness whereof I have hereunto signed the major diameter of the tooth-shank. my name in the presence of two Witnesses.

7 The combination with a holder or carrier having a seat for a removable tooth, of a tooth, HORACE ARNOLD 5 the body of which is provided with a through Witnesses:

tapped hole, adapted to receive a backing-out J. H. EARLY,

screw, as set forth. ROSALIE MANARD. 

